Wrist-pin and fastener for pistons.



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WRIST PIN AND FAS v j MfPLI''TIoN m. A 11,054,262, ,Patented-Fem@ 1913.

. Iwe l' hisjknzysf' 0 'UNUSED s'riirns PATENT orrion.

GEORGE E. WILSON, F STILLWATER, MINNESOTA, ASSIGNOR TO M. RUMELY\OM- P`ANY, OF LAPORTE, INDIANA, A CORPORATION OF INDIANA.

i WRIST-PIN AND FASTENER FOR P'ISTONS. i

insegne.

Specification of Letters Patent.

Application filed October 13, 1'911.

rai-emma Feb. 25,1913. serial No. 654,497. l

' engine pistons, and is especially adapted for use in connection withexplosive origines which usually have the crank rod connected directly to the interior of the piston.

Generally stated, the invention consists: of

the novel construction and arrangement ot'. 'part-s hereinafter described and defined in `the claims.

In explosive engines, it has beeny found extremely difficult to so securely connect a .wrist pin to a piston that it will not loosen up and move from its proper set position.

und r the continuous pounding action produced inthe. explosive action. In the first place, it is not desirable that the wrist pin be driven into the piston under great pressure or friction, and even when it is, it soon loosens, and, by. Contact with the cylinder, wears a groove therein and thereby soon puts the engine in bad running order.

In accordance with my invention, I provide the piston'with the tubular wrist pin oit such tit that it may be normally easily;

inserted in its seat in the piston or removed therefrom, and in connection with this tubular wrist pin, I provide an expanding device :tor distorting the seated cndsthereof, out ot true circular form, so that it will tightly tit in its seats in the piston. i

The preferred arrangement ot the invention is illustrated in the accompanying drawings whereim-like characters indicate like parts throughout the several Views.

ReferringI to the drawings, Figure l is a horizontal Isection with some parts broken away showing the improved wrist pin and fastener' applied to the piston ofan ordinary engine; Fig. 2 is a detail vlew with me parts sectioned showing the bushing xn end elevation and showing the erqiandinr device applied thereto. b

Ot the parts ot' the explosive engine. the numeral l il'ldicates the cylinder, thel numoral 2 the piston and the numeral 3 the crank rod. The piston 2, as is customary,

is provided Vwith diametrically oppositel transversely spaced intermcdiatclv )u'oiect-V ing wrist pin seats 2, between which the inner head of the crank rod i, closclv tits.

The tubular wrist pin 4 is preterabl.' made Vt'ro'in steel tubing and its ends quit-c closel)Y [it within the seats 2". mg or expanding in one direction. the ends oli' the tubular wrist pin 1l, I provide set screws 5 that are screw-threadcd 'through one wall of.' the said wrist pin, and impilire against the 'inner surlace of thc diametrically opposite wall. The projecting ends ol' these set screws .are passed loosely through clearance passages t5 in the pin seats 2a of the piston.

Then the set screws 5 are tightened, it is evident that they will expand thccnds of the wrist pin in theplanc ot the said set screws and thereby tighten the lsaid wrist pin within its seats Q under very great friction. The set screws should be arranged to thus expand the ends of the wrist pin on lines parallel to the direction of movements of the piston, and hence,'directly in the line ot' the strains produced by the explosions in the engine cylinder.

0f course, when the ends of the wrist pin are expanded in the direction stated, they will be slightly.contracted in a direction at 'fright angles thereto, but this has no detri- `mental effect because the ends of the sleeve are tightly held, in the direction in which the strains are applied to the wrist pin. The set screws are capable otbelng screwed so 'that there is no possibility oit the wrist pin becoming loose unless, of course, the set screws should turn, and themselves loosen up. To prevent this, a key or lock pin 7 is preferably provided through perforations in the said set screws, and its ends bent to prevent it from working out of position. The ends of the wrist pin are also preferably rounded od on the arc of the cylinder surface vso. that it' the wrist pin should not have been properly set or sutliciently expanded to hold it tight, the ends of the said For distort y Wrist pin would not Wear the cylinder rapidly, even if engaged therewith. The set screws 5, it will be noted, have `no engage-4 ment with the pist/on and do .not react against the saine directly but, in both directions, reacts directly against'the opposite sides of the ends of the Wrist. pin.

In actual'usage, this improved Wrist pin and Afastener have been found highly satisfactory in all respects.

What I claim is: 3

l. The combination with a tubular Wrist pin having contiguous yunbroken completely cylindrical. ends, of a set screw having threaded engagement with one Wall thereof and inipinging against the inner surface of the opposite Wall, forw expanding the saine in the r`direction of said set screw, substantially as described.

2. The combination with a tubular Wrist pin, of a set. screw applied to the ends thereof, and having end engagement With oney side of said Wrist pin and iinpinging against the inner surface of the opposite side thereof, for expanding the ends of the said Wrist pin in the direction lof said set screw, substantially as described.

The combination With a tubular Wrist pin having contiguous unbroken completely cylindrical ends, of a set screw applied to the ends thereof, vand having end engagenient with one side of said Wrist pin and viiiipinging against the inner surface of the opposite side thereof, fory expanding the ends of the said Wrist pin in the direction of said set screw, and a lock pin extended through perforations in said set screws and holding t-he saine against rotation. i

4. In an engine, the combination with a piston having inWardlyproject-ing pin seats, of a tubular Wrist pin having contiguous unbroken completely cylindrical ends With its ends in said pin seats, and set screws havingI threaded engagement with one side of the ends of said wrist pin, and iinpinging against the inner surface ofthe opposite sides thereof, for expanding the ends of said wrist pin in the direction of said sgh screws Within said seats, substantially as described.

5. In an engine, the combination with a piston having inwardly projectingy pin seats, of a tubular wrist pin having coiitignous unbroken completely cylindrical ends ii'ith its ends in said pin seats, and' Vset screws having threaded kengagement with one side-of the ends of said Wrist pin, and iinpinging against the inner surface of ythe opposite sides thereof, for expanding the ends of said wristpin in'one direction Within said seats, and a lock pin inserted throughv pei'foraticiis in the saidl set screws, v`sub staiitially as described. A* t In testimony xv iereof I affixy uiyrsignature in presence of two Witnesses.

GEORGE n. iviLsoN.

`Witnesses a Bnnxion G. ll/vi-IEELER, HARRLD. lliiioonii. 

